Damage to the protective sac that surrounds a foetus in the womb can be repaired in part by the foetus itself, a new study in humans and mice has shown.
Researchers at Kyoto University, Japan, investigated the innermost ‘amnion’ layer of the amniotic sac, which, if torn or ruptured, can often lead to premature birth.
Amniotic membranes normally remain intact until the onset of, or just before, active labour starts.
Figures from the US show that premature rupture of membranes affects an estimated 30%-40% of preterm births, a total 150,000 women per year.
However, the researchers found that the sac can sometimes also repair itself to avoid these problems.
By looking at both human and mouse amnions from different pregnancies, the study found that immune cells called macrophages in the foetus can be recruited to repair tears in the amniotic sac.
“We conclude that amnion has high regenerative potential… and that foetal macrophages are important in mediating this wound-repairing process,” said Yosuke Kawamura, of Kyoto, in the journal Science Signaling.